I have a 2.5 gallon acrylic Hex tank with a male Betta and a mystery snail. The tank has been completely cycled for quite some time now. The tank came as a package (TopFin AquaScene 2) with an undergravel filter. The filter seems to be working ok, but I keep hearing so many negative things about UGF filters. Plus, there seems to be a lot of surfarce agitation from the air pump bubbles and my Betta can't create bubble nests. I would like to replace the UGF with a small 3 gallon in-tank filter that I have in a different 2.5 gallon tank.
Is it ok to change fitler types in a cycled tank? If I do, do I have to re-cycle the tank? Do I need to completely clean out the bottom of the tank, below the UGF plate? Or just remove the plate?...
Answers:
UGF do suck in my opinion lol. I'm not real familiar with their set up, it's been over 10 years since I had one, but is there any kind of filter pad in them? If so, add that to the new filter. Beneficial bacteria grows all over the tank, in the gravel(so be sure you only rinse that in a bucket of used tank water, not tap water), any decorations in the tank, and the filter media. So, if there is no filter pad in the UGF to move to the new filter, there will still be some beneficial bacteria in the tank. It may go through a mini cycle, just monitor the levels and increase the water changes if you need to.
I would completely clean the bottom of the tank, because those UGF have a tendency to trap uneaten food and waste under there, which can cause an ammonia spike. I'd do a good gravel vac, remove the fish and about 1/2 the water and put the gravel in the bucket with the used tank water, then remove the UGF.
Also, is that new filter on an established tank that's been running? If so, then don't change the filter pad in that one, keep it on and it should be ok-no cycle.
Good luck!
No, you don't have to do the cycle again, just take out the ugf and replace it with the other one
EB
